The present invention and the problems on which it is based are explained here with respect to MEMS micromirror arrays, although, in principle, the present invention may be applied to any micromechanical components.
German Published Patent Application No. 10 2008 000 030 describes a manufacturing method for a micromechanical electrostatic adjusting device and a corresponding micromechanical electrostatic adjusting device, a mirror element being mounted via springs on a stationary region.
During operation or in the event of an overload, MEMS micromirrors may suffer damage in the form of cracks and/or breaks. If it cannot be detected promptly, such damage may cause safety-relevant problems for humans and machines.
To prevent such risks, it has been proposed that a monitoring method should be provided for detection of damage to such MEMS micromirror arrays.
For example, with MEMS micromirror arrays or with other MEMS structures, for example, actuators or sensors, optical monitoring units may be built into the overall module. The change in a beam of light reflected by the movable MEMS structure may be recorded by a photodiode. In the event of damage, signal changes in the photodiode are detected and transmitted to a monitoring ASIC. The ASIC then ensures an emergency cutoff or shutdown of a light source, for example, a laser light source.
If the micromechanical component includes a detection component in the form of a piezoresistive bridge circuit, the resistor element according to the present invention may be implemented by the fact that the detection component leads past a sensitive spot in the micromechanical component, which results in it being interrupted if damaged. In this case, the damage incident would be noticeable immediately due to loss of the detection signal, for example, the bridge output voltage.